/* 公共的样式 */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html,
body {
    /* height: 100%;

    background-image: url(../image/preview.gif);
    background-repeat: no-repeat;
    background-position: center;
    background-size: cover; */

    margin: 0;
    /* 去除默认边距 */
    height: 100vh;
    /* 设置高度为视口高度 */
    background-image: url(../image/cat.jpg);
    /* 替换为你的图片路径 */
    background-repeat: no-repeat;
    /* 防止背景图片重复 */
    background-position: center;
    /* 居中显示背景图片 */
    background-color: #f0f0f0;
    /* 可选：设置背景颜色以填充空白区域 */
    background-size: 100% auto;

}

.nav {
    height: 50px;

    background-color: rgb(50, 50, 50);
    color: white;

    line-height: 50px;
    padding-left: 20px;
}

.container {
    width: 100%;
    height: calc(100% - 50px);

    display: flex;
    align-items: center;
    justify-content: center;
}